Initial Questions to Explore

I’m wondering how many hunters are in each of the units I would expect that CPW associates the number of hunters to how many elk are in each unit.

I am also curious to know if the number of hunters has changed from year to year.

NOTICE that I am only looking at the general rifle hunting seasons on public land. There are also hunters in Archery, Muzzleloader, Private Land, Ranching for Wildlife, etc.

Setup

setwd("~/_code/colorado-dow/Phase I - Descriptive Analytics")

Load required libraries for wrangling data, charting, and mapping

library(plyr,quietly = T)
library(dplyr,quietly = T)
library(ggplot2, quietly = T)

Set our preferred charting theme

theme_set(theme_minimal())

Run script to get hunter data

source('~/_code/colorado-dow/datasets/Colorado Elk Harvest Data.R', echo=F)

Table of the data

COElkRifleAll

Statewide Elk Hunters

First lets look at the entire state as a whole

COElkHuntersStatewide <- summarise(group_by(COElkRifleAll,Year,Unit),
                                   Hunters = sum(c(Hunters.Antlered,Hunters.Antlerless,Hunters.Either),na.rm = T))

COElkHuntersStatewide <- summarise(group_by(COElkHuntersStatewide,Year),
                                   Hunters = sum(Hunters))

ggplot(COElkHuntersStatewide, aes(Year,Hunters)) +
  geom_bar(stat="identity") +
  coord_cartesian(ylim = c(120000,160000)) +
  labs(title="Statewide Elk Hunters", caption="source: cpw.state.co.us")

At a highpoint in 2006 of ~151000, the number of hunters decreased to a low in 2009 of ~133000. Since 2009 the total number of hunters has slightly increased from year to year.

Hunters by Unit

I’d like to know where the hunters are distributed across the state.

run script to get unit boundaries so we can draw them on a map

source('~/_code/colorado-dow/datasets/coordinate locations of cpw hunt units.R', echo=F)
## OGR data source with driver: ESRI Shapefile 
## Source: "/Users/psarnow/_code/colorado-dow/datasets/CPW_GMUBoundaries/BigGameGMUBoundaries03172015.shp", layer: "BigGameGMUBoundaries03172015"
## with 185 features
## It has 12 fields
## Integer64 fields read as strings:  GMUID

Get a statemap with some roads on it

roaddata <- rgdal::readOGR("~/_code/colorado-dow/datasets/ne_10m_roads/ne_10m_roads.shp")
## OGR data source with driver: ESRI Shapefile 
## Source: "/Users/psarnow/_code/colorado-dow/datasets/ne_10m_roads/ne_10m_roads.shp", layer: "ne_10m_roads"
## with 56601 features
## It has 29 fields
## Integer64 fields read as strings:  scalerank question
USAroads <- roaddata %>% subset(.,sov_a3 == "USA" & type == "Major Highway")
# I need to convert to data frames so that I can use the data with ggplot2.
USAroads <- fortify(USAroads)
Unitboundaries <- shapefile %>% fortify(region = "GMUID")

Unitboundaries2 <- merge(Unitboundaries, shapefile@data, by.x = 'id', by.y = 'GMUID')
Unitboundaries2$Unit <- as.character(Unitboundaries2$id)

# get min/max of long/lat for zooming
longset <- c(min(Unitboundaries2$long),max(Unitboundaries2$long))
latset <- c(min(Unitboundaries2$lat),max(Unitboundaries2$lat))
COroads <- filter(USAroads, long > longset[1] & long < longset[2])
COroads <- filter(COroads, lat > latset[1] & lat < latset[2])

# Hunters in each unit (Combine the seasons)
COElkUnitHunters <- summarise(group_by(COElkRifleAll,Year,Unit),
                              Hunters = sum(c(Hunters.Antlered,Hunters.Antlerless,Hunters.Either),na.rm = T))

Year2017 <- filter(COElkUnitHunters, Year == "2017")
HunterstoPlot <- left_join(Unitboundaries2,Year2017, by=c("Unit"))
ggplot(HunterstoPlot, aes(long, lat, group = group)) + 
  geom_polygon(aes(fill = Hunters),colour = "grey50", size = .2) + #Unit boundaries
  geom_path(data = COroads,aes(x = long, y = lat, group = group), color="#3878C7",size=2) + #Roads
  geom_text(data=data_centroids,aes(x=longitude,y=latitude,label = Unit),size=3) + #Unit labels
  scale_fill_distiller(palette = "Oranges",direction = 1,na.value = 'grey') +
  xlab("") + 
  ylab("") +
  theme(panel.background = element_rect(fill='white')) +
  theme(panel.grid.major= element_blank()) +
  theme(panel.grid.minor= element_blank()) +
  labs(title="2017 Colorado Elk Hunters", caption="source: cpw.state.co.us")

Conclusion

Its interesting that some of these units with high amount of hunters doesn’t seem to coincide with how many elk are in those units. The Northwestern herd seems to have the most amount of hunters, but our last report indicated that units with more elk in them were in the South and Southwest.

Lets investigate that further. Is there a correlation of number of hunters to number of elk in each unit? If not, I would certainly be interested in which units have the highest ratio of Elk to Hunters